BGN 19: Errata

Errata


The following text was omitted from the research note of S.P. Simons and S.C. Somerville. 1988. Investigations of a genetic instability in barley, BGN 18:37-45. The text below is the continuation of the text on page 40.

were found (data not presented). Thus, it appears that no true mutants were recovered in the original screen, and that the ADHI screen is less stringent than the waxy or disease reaction screens.

DISCUSSION

We report that we were unable to repeat the observation made by Wise and Ellingboe (1985) of a genetic instability in progeny derived from the cross CI-16151 X CI-16155. We tested the stability of three different loci and recovered no true mutants. It is difficult to reconcile our results with those of Wise and Ellingboe (1985) other than to suggest some environmental or genetic factor, absent in our experiment, is required to activate the destabilizing process in these lines.

Environmental stresses have been implicated in the activation of quiescent transposable elements (Nevers et al., 1986). Unlike the materials we used, the barley seeds used by Wise and Ellingboe were harvested prematurely and dried in order to reduce the generation time. It is possible that either the premature harvest or the heat treatment may have activated the genetic instability observed by Wise and Ellingboe (1985).

A second possible explanation for the discrepancy between the two results is that a genetic factor required to activate the instability at the Ml-a locus was missing in the parental lines utilized in the experiment described in this report. Although CI-16151 and CI-156155 were derived from the same seedstocks utilized by Wise and Ellingboe, the lines were subjected to a generation of single seed descent to ensure the genetic purity of the lines. A genetic factor, necessary for the expression of the instability, may have been present in a subset of either the CI-16151 or CI-16155 stocks, and may have been lost in this process.

In conclusion, we were unable to find evidence for an active transposable element system in these barley lines.

ACKNOWLEDGEMENTS

We would like to thank Lisa Churgay for her help in screening the F2 populations. R. Wise provided the suggestion that the difference in harvesting methods may account for the disparity in the two sets of results and we appreciate his helpfulness. We would also like to acknowledge the support of the U.S. Department of Energy (DE-AC02-76- ERO1338).

Michigan Agricultural Experiment Station Journal Article Number 12620.


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